Calm redirects here. For the character with the Japanese name Calm, see Calem (game).

Natures (Japanese: せいかくPersonality) are the Pokémon analogue of personalities. They were introduced in the Generation III games and remain a game mechanic in Generation IV and Generation V. Every Pokémon in these games has one of these 25 Natures, listed and described in the section below.

A Pokémon's Nature usually affects the growth rate of two of its stats, ultimately increasing one of its stats by 10% and decreasing another by 10%. Natures also determine the Pokémon's favorite flavor and its disliked flavor. Each stat is tagged to a flavor (e.g. Attack-Spicy), and if the Nature boosts the stat, the tagged flavor will be the Pokémon's favorite (i.e. Lonely boosts Attack, hence a Lonely-natured Pokémon's favorite flavor is Spicy). The opposite also holds true (i.e. Bold hinders Attack, so a Bold-natured Pokémon will dislike Spicy food).

Pokemon's natures are determined when it is generated by the game; when it is obtained as an Egg from the Pokémon Day Care, encountered in the wild, or given to the player by an NPC.

Every Nature represents one of the 25 unique possible combinations of stat increase and decrease; thus, there are five Natures that have no effect on the Pokémon's stat growth (Bashful, Docile, Hardy, Quirky and Serious). These five "neutral" Natures are technically Natures that increase and decrease the same stat.

From Emerald onwards, a Ditto or a female Pokémon that holds an Everstone has a 50% chance of passing its Nature to its offspring when at the Pokémon daycare. Since HeartGold and SoulSilver, male Pokémon can also pass on their Nature with an Everstone. In Generation IV, parents could only pass Natures to their offspring if both Pokémon and the Trainer all came from a game in the same language. Also from Emerald onwards, if a Pokémon with the AbilitySynchronize is leading the party, there is a 50% chance of encountering a wild Pokémon with the same Nature. Synchronize affects any encounter, including stationary legends, but excluding Pokémon that are received from an NPC, such as the Eevee given out by Bill in HeartGold and SoulSilver, Pokémon received in a museum after being resurrected from Fossils, or catching Pokémon during a Stroll in the Pokéwalker bundled with HeartGold and SoulSilver.

Natures also dictate the manner in which Pokémon battle by themselves at the Battle Palace, different Natures (including the five non-increasing/decreasing ones) make the Pokémon use different methods of attacks and change tactics when they are low on health. A man in a house closest to the Sunyshore City Heritage Site asks to see Pokémon with different Natures (Serious, Naive and Quirky), and will give the player three Pokétch applications.

From HeartGold and SoulSilver and on, the stat increased or decreased by a Pokémon's Nature has a red or blue shadow respectively when viewing that Pokémon's summary screen.

In Generation V games, Trainers themselves have Natures. This Nature can be viewed and changed on the Trainer Card. These Natures affect what the player will say on others' games at Unity Tower.

All Natures have a set ratio of Attack, Defense, and Support moves; these change when the Pokémon's HP falls below 50%. This represents the likelihood a particular category of attack is chosen. During battle, a random attack from the Pokémon's moveset in the selected category is chosen; if no such attack exists, the Pokémon will "appear incapable of using its power", and will skip its turn.

The following table lists each Nature and its move type preferences; it may be rearranged by clicking the boxes next to each column's heading.